1. Field of the Invention
The present invention relates to an electrolytic cation exchange membrane. More particularly, the present invention relates to a cation exchange membrane suitable for use in electrolysis of water or an aqueous solution such as an aqueous acidic or alkaline solution, an aqueous alkali metal halide solution or an aqueous alkali metal carbonate solution.
2. Description of the Prior Art
As a process for producing an alkali metal hydroxide and chlorine by the electrolysis of the above-mentioned aqueous solution, particularly an aqueous solution of an alkali metal chloride, a diaphragm method has now been used in place of a mercury method with a view to preventing environmental pollution. Further, in order to efficiently obtain an alkali metal hydroxide having a high purity in a high concentration, it has been proposed and put into practical use to employ an ion exchange membrane.
On the other hand, from the standpoint of energy saving, it is desired to improve the current efficiency and minimize the cell voltage in the electrolysis of this type. For this purpose, various methods have been proposed. However, this object has not yet adequately been attained.
Therefore a need still exists for an improved cation exchange membrane having a high current efficiency and a low cell voltage in the electrolysis of aqueous solutions.